Fluid end with non-circular bores and closures for the same

ABSTRACT

A closure element for a fluid end of a reciprocating pump is installable within a segment of a casing of the fluid end to substantially close the segment. The closure element includes a main body that extends from an interior surface to an exterior surface, and at least a portion of the main body has a non-circular cross-sectional shape. A fluid end of the closure element may include a plurality of segments and at least a portion of at least one segment of the plurality of segments may have a non-circular cross-sectional shape configured to receive and secure a closure element with a non-circular cross-sectional shape.

FIELD OF INVENTION

The present invention relates to the field of high pressurereciprocating pumps and, in particular, to fluid ends of high pressurereciprocating pumps and closure and/or sealing assemblies for the same.

BACKGROUND

High pressure reciprocating pumps are often used to deliver highpressure fluids during earth drilling operations. One or more sealingarrangements are typically provided in the fluid end to seal conduitsformed in the fluid end and prevent, or at least discourage, leakage.More specifically, the fluid end may define one or more internal pumpingchambers and conduits may define pathways between the one or moreinternal pumping chambers and external surfaces of the fluid end. Atleast some segments of these conduits may be sealed with a closureassembly that may include a closure element (e.g., a cover, plug, and/orsleeve), a seal element, and a retaining element. Alternatively, aclosure assembly may include some subset of these elements. In any case,seals in a fluid end segment may prevent, or at least discourage,leakage through the conduits of a fluid end.

SUMMARY

The present application relates to techniques for closing a segment of afluid end of a high pressure reciprocating pump. The techniques may beembodied as a closure element and/or a closure assembly, either of whichmay be provided independent of any other elements or as part of a fluidend, a kit, and/or a reciprocating pump. Additionally, the techniquesmay be embodied as a fluid end and as a method for closing a segment ofa fluid end of a high pressure reciprocating pump.

More specifically, in accordance with at least one embodiment, thepresent application is directed to a closure element for a fluid end ofa reciprocating pump. The closure element is installable within asegment of a casing of the fluid end to substantially close the segmentand includes a main body that extends from an interior surface to anexterior surface. At least a portion of the main body has a non-circularcross-sectional shape.

Among other advantages, the non-circular shape creates sealing andretaining options that may be advantageous as compared to traditionalsealing and retaining techniques. For example, the closure element maybe self-retaining and/or may be retained within a bore withoutthreading, which is often a high-stress point that is prone to failure.More specifically, closure elements are often secured in a segment witha retaining element that is secured to a fluid end via a threadedconnection formed between threads machined into the fluid end andthreads of the retaining element. These threads are typically subject tohigh levels of cyclical stress and, thus, if the retaining element isnot installed or preloaded correctly, the threads may experience fatiguefailure.

Still further, the non-circular cross-sectional shape allows a sealinglocation to move inwards, adjacent a pumping chamber, or outwards,adjacent an exterior of the fluid end, each of which may provideadditional life span advantages for the closure element and/or the fluidend within which the closure element is installed. For example, aclosure element with a non-circular cross-sectional shape may beretained adjacent the pumping chamber of a fluid end and may protect theinterior edges of a fluid end segment, which are often a point offailure, from wear. Additionally or alternatively, when the closureelement is retained adjacent the pumping chamber or external surface,the closure element can define a corner for a corner seal, which mayavoid traditional pitfalls associated with radial seals (i.e., outerdiameter seals) used on closure elements for fluid ends. For example,when a closure element has a non-circular cross-sectional shape, a boreor corner seal may be used to seal around the closure element. Stillfurther, in some instances, the sealing area can be located on aremovable piece. Then, if the sealing surface becomes damaged (whichtypically happens over time during normal pumping operation), thesealing area can be repaired via a part replacement instead of via aninvasive repair (e.g., a weld repair).

In at least some embodiments, the non-circular cross-sectional shape isan extended ovular shape. This shape may ensure that the closure elementis removable from, but also securable within, a bore segment of a fluidend. Additionally or alternatively, the main body may include a seatingsection proximate the interior surface and a closure section proximatethe exterior surface, one or both of which may have the non-circularcross-sectional shape. For example, the seating section may extendradially beyond the closure section, the seating section may have afirst non-circular cross-sectional shape, and the closure section mayhave a second non-circular cross-sectional shape that is smaller thanthe first non-circular cross-sectional shape. Alternatively, the seatingsection may extend radially beyond the closure section and only one ofthe seating section and the closure section may include the non-circularcross-sectional shape. In either case, the two sections may allow theclosure element to be secured within the fluid end, e.g., against thefluid end and/or a retaining element, and/or to form a corner seal whensecured within a fluid end bore segment.

In at least some instances where the seating section extends radiallybeyond the closure section, the seating section may define anon-circular shoulder between the seating section and the closuresection. In some of these embodiments, the closure section defines aseal channel adjacent or proximate to the non-circular shoulder. Eitherway, this allows some flexibility for the sealing area and may,advantageously, move the sealing area away from locations that are hardto repair. Still further, in some embodiments, the closure elementincludes one or more installation elements disposed on and extendingaway from the exterior surface so that that the one or more installationelements are accessible from an exterior of the segment of the casing ofthe fluid end when the closure element is installed within the segment.Such elements may enable a user to easily install or remove the closureelement from a fluid end bore segment.

In accordance with additional embodiments, the present application isdirected to a closure assembly. The closure assembly may be formed withthe foregoing closure element embodiments, as well as variationsthereof. Thus, the closure assembly may realize any of the foregoingadvantages. Additionally, the closure assembly includes a retainingassembly that is coupleable to the exterior surface of the closureelement. Generally, the retaining assembly may prevent, or at leastdiscourage, the closure element from being blown out (i.e., removed) ofa bore segment, e.g., by pressure in a pumping chamber. In someembodiments, the retaining assembly may also prevent, or at leastdiscourage, the closure element from being sucked into a pumping chamberof the fluid end (e.g., during an intake stroke of a reciprocatingcomponent operating in or adjacent the fluid end).

In at least some embodiments, the retaining assembly also includescouplers that connect the removably couple a retaining element to theclosure element. Additionally or alternatively, the retaining assemblymay be configured to be disposed entirely within the segment of thecasing of the fluid end when the closure element is installed within thesegment of the casing of the fluid end. In fact, in such embodiments,the retaining assembly may appear to be part of the closure element and,thus, such embodiments may sometimes be referred to as “two-part closureelement” embodiments. Among other advantages, such embodiments may allowa closure element to seal adjacent a pumping chamber, potentiallyreducing the size of the pumping chamber, which is advantageous forpumping compressible fluids. Additionally or alternatively, a retainingassembly disposed within a fluid end bore may reduce the overallfootprint of a fluid end (since the retaining assembly does not extendtherefrom), potentially reducing snag/trip hazards around the fluid end(e.g., as compared to retaining assemblies that protrude from a fluidend).

Alternatively, in some instances, at least a portion of the retainingassembly is configured to be disposed at least partially exteriorly ofthe casing of the fluid end when the closure element is installed withinthe segment of the casing of the fluid end. For example, the retainingassembly may include an annular retaining ring with a non-circular crosssection disposed exteriorly of the casing of the fluid end. The annularretaining ring can define a seat on which a shoulder of the portion ofthe main body of the closure element with the non-circularcross-sectional shape may sit. Then, the sealing area for the closureelement may be formed against this annular ring, which can be easilyrepaired or replaced (e.g., without invasive repairs). Moreover, in atleast some embodiments, the retaining ring may be secured to a fluid endwith a plurality of couplers, but need not be removed to replace theclosure element. Instead, the non-circular cross-sectional shape of theclosure element may allow the closure element to be replaced or servicedquickly, without removing plurality of couplers (e.g., by rotating theclosure element into an installation/removal orientation while theretaining ring remains in place).

In accordance with additional embodiments, the present application isdirected to a fluid end of a reciprocating pump including a casing withintersecting conduits that collectively define a plurality of segmentsextending from an external surface of the casing to a pumping chamberdefined within the casing. At least a portion of at least one segment ofthe plurality of segments has a non-circular cross-sectional shapeconfigured to receive and secure a closure element with a non-circularcross-sectional shape. At least because of the non-circularcross-sectional shape, this fluid end may realize many of the advantagesdiscussed above in connection with the closure elements and/or theclosure assemblies presented herein.

In some embodiments, the plurality of segments include an intake segmentthat provides a fluid inlet for the pumping chamber, a discharge segmentthat that provides a fluid outlet for the pumping chamber, areciprocation segment, and an access segment. The reciprocation segmentis configured to operably couple a reciprocating component to thepumping chamber so that the reciprocating component can draw fluid intothe pumping chamber via the intake segment and discharge fluid from thepumping chamber via the discharge segment. The access segment providesaccess to at least the pumping chamber. In some instances, the accesssegment has the non-circular cross-sectional shape. Additionally oralternatively, the discharge segment may have the non-circularcross-sectional shape.

Regardless of the segments included in a fluid end, the portion of theat least one segment of the plurality of segments that has thenon-circular cross-sectional shape may comprise a segment portionadjacent to the pumping chamber. Alternatively, the portion of the atleast one segment of the plurality of segments that has the non-circularcross-sectional shape may comprise a segment portion adjacent to theexternal surface of the casing.

In accordance with additional embodiments, the present application isdirected to a method of closing an externally open segment of a fluidend of a reciprocating pump with a closure assembly. The method includesinserting a non-circular closure element into a segment of a fluidcasing in a first direction while the non-circular closure element isdisposed in a first orientation. Then, the non-circular closure elementis rotated to a second orientation that is angularly offset from thefirst orientation with respect to at least one axis of rotation. Afterand/or during the rotation, the non-circular closure element is movedwithin the segment of a fluid casing in a second direction. The seconddirection is opposite the first direction and, thus, causes thenon-circular closure element to seat within the segment. In some ofthese embodiments, the rotating occurs in a pumping chamber of the fluidend and involves a first rotation of approximately ninety degrees abouta first axis of rotation and a second rotation of approximately ninetydegrees about a second axis of rotation.

Notably, among other advantages, the closure element can be seated intoa bore segment without a retaining element and/or without threading. Atleast because this method utilizes a non-circular closure element, thismethod may also realize any advantages described above. This method mayalso be executed with any variations of closure elements or closureassemblies described herein.

The foregoing advantages and features will become evident in view of thedrawings and detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

To complete the description and in order to provide for a betterunderstanding of the present application, a set of drawings is provided.The drawings form an integral part of the description and illustrateembodiments of the present application, which should not be interpretedas restricting the scope of the invention, but just as examples. Thedrawings comprise the following figures:

FIG. 1 is a perspective view of a prior art reciprocating pump includinga fluid end.

FIG. 2 is a cross sectional view of another prior art fluid end.

FIG. 3 is a front view of a fluid end with a non-circular bore that hasnon-circular closure assemblies installed therein. The fluid end andclosure assemblies are each formed according to example embodiments ofthe present application.

FIG. 4 is a side, sectional view of the fluid end of FIG. 3 taken alongline “A-A” of FIG. 3 .

FIG. 5 is a perspective view of one of the closure assemblies installedin the fluid end of FIGS. 3 and 4 .

FIG. 6 is a front, sectional view of the fluid end of FIG. 3 taken alongline “A-A” of FIG. 4 , with the closure assembly removed from the fluidend.

FIG. 7 is a detail view of a portion of the sectional view of FIG. 4with the closure assembly removed from the fluid end.

FIG. 8 is a detail view of portion “B” of the sectional view of FIG. 4 .

FIG. 9 is a side, sectional view of a portion of another exampleembodiment of a fluid end with a non-circular bore formed in accordancewith the present application.

FIG. 10 is a perspective view of a second embodiment of a closureassembly formed in accordance with the present application.

FIG. 11 is a front view of a portion of the fluid end of FIG. 3 with athird embodiment of the closure assembly presented herein installedtherein.

FIG. 12 is a side, sectional view of the fluid end and closure assemblyof FIG. 11 .

FIG. 13 is a side, sectional view of another example embodiment of afluid end with a non-circular bore including a fourth embodiment of theclosure assembly installed therein. The fluid end and closure assemblyare each formed according to example embodiments of the presentapplication.

FIG. 14 is a perspective view of the closure assembly shown in FIG. 13 .

FIG. 15 is a detail view of portion “B” of the sectional view of FIG. 13.

FIG. 16 is a side perspective, sectional view of yet another exampleembodiment of a fluid end with a non-circular bore including a fifthembodiment of the closure assembly presented herein installed therein.The fluid end and closure assembly are each formed according to exampleembodiments of the present application.

FIG. 17 is a front view of the fluid end of FIG. 16 , with a closureelement of the closure assembly for the fluid end being shown in aninstallation orientation.

FIGS. 18A-18E depict a method of closing an externally open segment of afluid end of a reciprocating pump with a non-circular closure assembly,according to an example embodiment of the present application.

Like reference numerals have been used to identify like elementsthroughout this disclosure.

DETAILED DESCRIPTION

The following description is not to be taken in a limiting sense but isgiven solely for the purpose of describing the broad principles of theinvention. Embodiments of the invention will be described by way ofexample, with reference to the above-mentioned drawings showing elementsand results according to the present invention.

Generally, the present application is directed to a fluid end of areciprocating pump, closure assemblies for the fluid end, and/orportions thereof. The fluid end presented herein has at least one borewith a non-circular cross-sectional shape while the closure assembliespresented herein include least some components or sections withnon-circular cross-sectional shapes. Typically, fluid ends forreciprocating pumps have bores with circular cross-sectional shapes(e.g., cylindrical bores) while closure elements therefor (e.g., valvecovers, plugs, sleeves, etc.) have corresponding circular/cylindricalshapes to allow the closure elements to close and/or seal the bore.

These circular/cylindrical closure elements are typically secured in abore segment with a threaded retaining element that engages threadsmachined into the fluid end. Overall, such an arrangement creates atleast two issues. First, a cylindrical closure element secured in acylindrical bore can define sealing areas on the inner surface of thebore. This surface is often defined by the fluid end and, thus, can bevery difficult to repair (e.g., repair may require an invasive weldrepair). Second, with such an arrangement, the threads on the retainingelement are subject to high levels of cyclical stress. Thus, if theretaining element is not preloaded correctly, the threads may experiencefatigue failure.

The closure assemblies and/or the fluid end presented herein resolvethese issues and, thus, can extend the lifespan of both the fluid endand the closure element. Initially, in at least some embodiments, aclosure element with a non-circular cross-sectional shape can be securedwithin a fluid end bore without a threaded retaining element, therebyeliminating a potential point of failure. Instead, the closure elementcan be retained directly on a fluid end and/or on a retaining elementthat is fixed in place on a fluid end (e.g., the retaining element neednot be removed for installation or removal of the closure element). Thismay also make the closure assembly easy to install, decreasing theamount of time required for installation and/or removal which, in turn,decreases downtime. Moreover, in at least some embodiments where a sealdisposed around a closure element seals against a retaining element, thefluid end will not define a sealing area and, thus, will not experiencewear associated with the sealing area. Additionally or alternatively,the non-circular cross-sectional shapes of the present application mayallow the seals to be/provide bore or corner seals, which may be morerobust than radial seals (e.g., seals between nested components ofdifferent radial dimensions).

Now referring to FIG. 1 for a description of a prior art reciprocatingpump 100. The reciprocating pump 100 includes a power end 102 and afluid end 104. The power end 102 includes a crankshaft that drives aplurality of reciprocating plungers within the fluid end 104 to pumpfluid at high pressure. Generally, the power end 102 is capable ofgenerating forces sufficient to cause the fluid end 104 to deliver highpressure fluids to earth drilling operations. For example, the power end102 may be configured to support hydraulic fracturing (i.e., fracking)operations, where fracking liquid (e.g., a mixture of water and sand) isinjected into rock formations at high pressures to allow natural oil andgas to be extracted from the rock formations. However, to be clear, thisexample is not intended to be limiting and the present application maybe applicable to both fracking and drilling operations.

Often, the reciprocating pump 100 may be quite large and may, forexample, be supported by a semi-tractor truck (“semi”) that can move thereciprocating pump 100 to and from a well. Specifically, in someinstances, a semi may move the reciprocating pump 100 off a well whenthe reciprocating pump 100 requires maintenance. However, areciprocating pump 100 is typically moved off a well only when areplacement pump (and an associated semi) is available to move intoplace at the well, which may be rare. Thus, often, the reciprocatingpump is taken offline at a well and maintenance is performed while thereciprocating pump 100 remains on the well. If not for this maintenance,the reciprocating pump 100 could operate continuously to extract naturaloil and gas (or conduct any other operation). Consequently, anyimprovements that extend the lifespan of components of the reciprocatingpump 100, especially typical “wear” components, and extend the timebetween maintenance operations (i.e., between downtime) are highlydesirable.

Still referring to FIG. 1 , but now in combination with FIG. 2 , invarious embodiments, the fluid end 104 may be shaped differently and/orhave different features, but may still generally perform the samefunctions, define similar structures, and house similar components. Toillustrate potential shape variations, FIG. 2 shows a side, sectionalview of a fluid end 104′ with different internal and external shaping ascompared to fluid end 104. However, since fluid end 104 and fluid end104′ have many operational similarities, FIGS. 1 and 2 are labeled withthe same reference numerals and are both described with respect to thesecommon reference labels.

The sectional view of FIG. 2 is taken along a central or plunger axis ofone of the plungers 202 included in a reciprocating pump 100. Thus,although FIG. 2 depicts a single pumping chamber 208, it should beunderstood that a fluid end 104 can include multiple pumping chambers208 arranged side-by-side. In fact, in at least some embodiments (e.g.,the embodiment of FIG. 1 ), a casing 206 of the fluid end 104 forms aplurality of pumping chambers 208 and each chamber 208 includes aplunger 202 that reciprocates within the casing 206. However,side-by-side pumping chambers 208 need not be defined by a single casing206. For example, in some embodiments, the fluid end 104 may be modularand different casing segments may house one or more pumping chambers208. In any case, the one or more pumping chambers 208 are arrangedside-by-side so that corresponding conduits are positioned adjacent eachother and generate substantially parallel pumping action. Specifically,with each stroke of the plunger 202, low pressure fluid is drawn intothe pumping chamber 208 and high pressure fluid is discharged. But,often, the fluid within the pumping chamber 208 contains abrasivematerial (i.e., “debris”) that can damage seals formed in thereciprocating pump 100.

As can be seen in FIG. 2 , the pumping paths and pumping chamber 208 ofthe fluid end 104 are formed by conduits that extend through the casing206 to define openings at an external surface 210 of the casing 206.More specifically, a first conduit 212 extends longitudinally (e.g.,vertically) through the casing 206 while a second conduit 222 extendslaterally (e.g., horizontally) through the casing 206. Thus, conduit 212intersects conduit 222 to at least partially (and collectively) definethe pumping chamber 208. In the prior art fluid end 104 and prior artfluid end 104′, conduits 212 and 222 are substantially cylindrical, butthe diameters of conduit 212 and conduit 222 may vary throughout thecasing 206 so that conduits 212 and 222 can receive various structures,such as sealing assemblies or components thereof.

Regardless of the diameters of conduit 212 and conduit 222, each conduitmay include two segments, each of which extend from the pumping chamber208 to the external surface 210 of the casing 206. Specifically, conduit212 includes a first segment 2124 and a second segment 2126 that opposesthe first segment 2124. Likewise, conduit 222 includes a third segment2224 and a fourth segment 2226 that opposes the third segment 2224. Inthe depicted embodiment, the segments of a conduit (e.g., segments 2124and 2126 or segments 2224 and 2226) are substantially coaxial while thesegments of different conduits are substantially orthogonal. However, inother embodiments, segments 2124, 2126, 2224, and 2226 may be arrangedalong any desired angle or angles, for example, to intersect pumpingchamber 208 at one or more non-straight angles.

In the depicted embodiment, conduit 212 defines a fluid path through thefluid end 104. Segment 2126 is an intake segment that connects thepumping chamber to a piping system 106 delivering fluid to the fluid end104. Meanwhile, segment 2124 is an outlet or discharge segment thatallows compressed fluid to exit the fluid end 104. Thus, in operation,segments 2126 and 2124 may include valve components 51 and 52,respectively, (e.g., one-way valves) that allow segments 2126 and 2124to selectively open. Typically, valve components 51 in the inlet segment2126 may be secured therein by a piping system 106. Meanwhile valvecomponents 52 in outlet segment 2124 may be secured therein by a closureassembly 53 that, in the prior art example depicted in FIG. 2 , includesa closure element 251 (also referred to as a discharge plug) that issecured in the segment 2124 by a retaining assembly 252. Notably, theprior art retaining assembly 252 is coupled to segment 2124 via threads2128 defined by an interior wall of segment 2124.

On the other hand, segment 2226 defines, at least in part, a cylinderfor plunger 202, and/or connects the casing 206 to a cylinder forplunger 202. For example, in the depicted embodiment, a casing segment35 is secured to segment 2226 and houses a packing assembly 36configured to seal against a plunger 202 disposed interiorly of thepacking assembly 36. In any case, reciprocation of a plunger 202 in oradjacent to segment 2226, which may be referred to as a reciprocationsegment, draws fluid into the pumping chamber 208 via inlet segment 2126and pumps the fluid out of the pumping chamber 208 via outlet segment2124. Notably, in the depicted prior art arrangement, the packingassembly 36 is retained within casing segment 35 with a retainingelement 37 that is threadably coupled to casing segment 35.

Segment 2224 is an access segment that can be opened to access to partsdisposed within casing 206 and/or surfaces defined within casing 206.During operation, access segment 2224 may be closed by a closureassembly 54 that, in the prior art example depicted in FIG. 2 , includesa closure element 254 (also referred to as a suction plug) that issecured in the segment 2224 by a retaining assembly 256. Notably, theprior art retaining assembly 256 is coupled to segment 2224 via threads2228 defined by an interior wall of segment 2224. However, in someembodiments, conduit 222 need not include segment 2224 and conduit 222may be formed from a single segment (segment 2226) that extends from thepumping chamber 208 to the external surface 210 of casing 206.

Overall, in operation, fluid may enter fluid end 104 (or fluid end 104′)via multiple openings, as represented by opening 216 in FIG. 2 , andexit fluid end 104 (or fluid end 104′) via multiple openings, asrepresented by opening 214 in FIG. 2 . In at least some embodiments,fluid enters openings 216 via pipes of piping system 106, flows throughpumping chamber 208 (due to reciprocation of a plunger 202), and thenflows through openings 214 into a channel 108. However, piping system106 and channel 108 are merely example conduits and, in variousembodiments, fluid end 104 may receive and discharge fluid via anynumber of pipes and/or conduits, along pathways of any desirable size orshape.

Also, during operation of pump 100, the first segment 2124 (of conduit212), the third segment 2224 (of conduit 222), and the fourth segment2226 (of conduit 222) may each be “closed” segments. By comparison, thesecond segment 2126 (of conduit 212) may be an “open” segment thatallows fluid to flow from the external surface 210 to the pumpingchamber 208. That is, for the purposes of this application, a “closed”segment may prevent, or at least substantially prevent, direct fluidflow between the pumping chamber 208 and the external surface 210 of thecasing 206 while an “open” segment may allow fluid flow between thepumping chamber 208 and the external surface 210. To be clear, “directfluid flow” requires flow along only the segment so that, for example,fluid flowing from pumping chamber 208 to the external surface 210 alongsegment 2124 and channel 108 does not flow directly to the externalsurface 210 via segment 2124.

Now turning to FIGS. 3 and 4 , these Figures depict a front view and aside, sectional view, respectively, of an example embodiment of a fluidend 304 formed in accordance with the present application. Additionally,in these Figures, an example embodiment of a closure assembly 400 formedin accordance with the present application is shown installed in thefluid end 304. For simplicity and clarity, these Figures continue to usesome reference numerals from the prior art illustrated in FIGS. 1 and 2; however, such continuity should not be construed as limiting in anymanner and, instead, is only utilized for ease of understanding.

In fact, FIGS. 3 and 4 should not be construed as limiting in anymanner. For example, while FIGS. 3 and 4 depict a fluid end 304 withnon-circular access segments 3224 that are sealed by non-circularclosure assemblies 400, any desirable segments of a fluid end formed inaccordance with the present application may be non-circular. That is,segments 2124, 2126, and/or 2226 could be non-circular, either inaddition to or instead of non-circular access segments 3224.Additionally or alternatively, only some segments of a particular typeof segment could be non-circular (e.g., a subset of the access segments3224 depicted in FIGS. 3 and 4 ). Still further, while FIGS. 3 and 4only depict closure assemblies 400 in non-circular access segments 3224,as mentioned, in operation, segment 2124, segment 3224, and segment 2226are each be completely capped, sealed, plugged, or otherwise closed toprevent fluid from passing through one of these segments to the externalsurface 310 of casing 306.

Still referring to FIGS. 3 and 4 , but now in combination with FIG. 5 ,the closure assembly 400 depicted in these Figures includes at least asealing assembly 401 formed by a closure element 402 and a seal 460. Insome embodiments (an example of which is described below), the sealingassembly 401 is self-retaining and, thus, can be installed within anon-circular segment 3224 without any additional components. However, inthe embodiment depicted in FIGS. 3-5 , the closure assembly 400 alsoincludes a retaining assembly 470 that retains the assembly 401 within anon-circular segment 3224. More specifically, the retaining assembly 470is removably coupleable to the closure element 402 and, when coupledthereto, retains the seal 460 adjacent the closure element 402. However,the retaining assembly 470 may also serve to retain the closure element402 within the non-circular segment 3224. For example, in someembodiments, the retaining assembly 470 may retain the closure element402 in the non-circular segment 3224 when a suction stroke of areciprocating component (e.g., plunger 202) urges the closure element402 into the pumping chamber 308 of the fluid end 304.

As can be seen in FIGS. 4 and 5 , the closure element 402 includes amain body that extends from an interior surface 406 to an exteriorsurface 410. When the closure element 402 is installed in thenon-circular segment 3224, the interior surface 406 is disposed closerto the pumping chamber 308 than the exterior surface 410. That is, theinterior surface 406 may be “upstream” (i.e., closer to the pumpingchamber 308) of the exterior surface 410. Or, from another perspective,the exterior surface 410 may be “downstream” of the interior surface406. In fact, in the particular embodiment of at least FIGS. 3-5 , theinterior surface 406 of the closure element 402 is disposed in oradjacent to the pumping chamber 308 when the closure element 402 isinstalled in the non-circular segment 3224. This position may beadvantageous not only because it allows the closure assembly 400 to besecured in place without threads, but also because it reduces theoverall size of the pumping chamber 308, which is typically advantageouswhen pumping compressible fluids (i.e., fluids for which thereciprocating pump 100 is intended). To help smooth pressure gradientsacross the interior surface 406 (e.g., created by fluid moving throughthe pumping chamber 308), the interior surface 406 may include taperededges 408.

It is possible to install the closure element 402 in or adjacent thepumping chamber 308 because the overall shape (e.g., the largestdimension) of the closure element 402 is non-circular so that theclosure element 402 has an elongated overall dimension 442 and a narrowoverall dimension 444, which is smaller than the elongated overalldimension 442. As is described in detail below, dimensions 442 and 444allow the closure element 402 to be easily inserted into and seatedagainst a non-circular portion of the non-circular segment 3224.

The features of the closure element 402 also facilitate this positioningand installation. More specifically, moving from the exterior surface410 to the interior surface 406, the closure element 402 includes aclosure section 430 and a seating section 438. That is, the closureelement 402 includes a closure section 430 adjacent, or at leastproximate, to the exterior surface 410 and a seating section 438adjacent, or at least proximate, to the interior surface 406. Theseating section 438 extends radially beyond the seating section 438 and,thus, defines a shoulder 436 between the closure section 430 and theseating section 438. As is described in further detail below, shoulder436 can engage (e.g. sit on) a seat of the non-circular segment 3224 tosecure, or at least orient/align, the closure element 402 within thenon-circular segment 3224.

In the depicted embodiment, the closure section 430 has a radial surface432 that has a non-circular cross-sectional shape. Similarly, theseating section 438 has a radial surface 439 that has a non-circularcross-sectional shape. In fact, the radial surface 439 of the seatingsection 438 and the radial surface 432 of the closure section 430 havenon-circular cross-sectional shapes that are substantially the same.That is, the closure section 430 has a first non-circularcross-sectional shape and the seating section 438 has a secondnon-circular cross-sectional shape that is smaller than, but similarlyproportioned to, the first non-circular cross-sectional shape.Consequently, the closure section 430 and the seating section 438 definea shoulder 436 with a face 437 of substantially constant width and ofsubstantially the same shape as the radial surface 439 and the radialsurface 432. In the depicted embodiment, the non-circular shape of thesevarious sections or features is an elongated oval, insofar as “elongatedoval” or variations thereof, such as “elongated ovular shape,” are usedto denote a shape formed from two semi-circular lines connected bystraight lines. However, this is just an example and other non-circularshapes, including one or more ellipses, can be used to achieve anon-circular shape.

In fact, all of the depicted shaping and dimensioning is provided as anexample and other embodiments need not have such dimensions and/orshaping. Instead, the closure element 402, and the assembly 401 overall,should have dimensions and shaping that correspond with the dimensionsand shaping of the non-circular segment 3224. For example, in someembodiments, the seating section 438 might have a non-circular shape andthe closure section 430 might have a different non-circular shape oreven a circular shape. In fact, in some embodiments, it may beadvantageous to have a circular closure section 430. This is becausemachining non-circular shapes may be more difficult than machiningcircular shapes. When the closure element 402 includes a circularclosure section 430, the non-circular segment 3224 may also include acorresponding circular section. Consequently, a circular closure section430 may decrease the amount of complex machining required to manufacturethe closure element 402 and non-circular segment 3224, which may lowerthe costs associated with manufacturing the fluid end 304 and theclosure assembly 400 presented herein.

However, to preserve the advantages of the non-circular overall shape ofthe closure assembly 400, when the closure section 430 has a circularshape or a non-circular shape that differs from the non-circular shapeof the seating section 438, the overall dimensions of the closuresection 430 should not extend beyond the narrow overall dimension 444 ofthe closure element 402. Any extension beyond the narrow overalldimension 444 might restrict or prevent the closure element 402 frombeing installed in the non-circular segment 3224. In any case, if onlyone of the closure section 430 and the seating section 438 includes anon-circular cross-sectional shape, the shoulder 436 may have adifferent shape than both of these sections. This is because an innerboundary of the shoulder 436 is defined by the closure section 430 andthe outer boundary of the shoulder 436 is defined by the seating section438.

Still referring to FIGS. 4 and 5 , in this embodiment, the closureassembly 400 includes a retaining assembly 470 that is coupled directedto the exterior surface 410 of the closure element 402 and inserted intothe non-circular segment 3224 with the closure element 402. That is, theretaining assembly 470, which includes a retaining element 472 andcouplers 495, is configured to be disposed entirely within thenon-circular segment 3224 of the casing 306 of the fluid end 304 whenthe closure element 402 is installed within the non-circular segment3224 to substantially close the non-circular segment 3224. Accordingly,the exterior surface 410 includes a variety of features to securelymount and couple the retaining assembly 470 to the closure element 402.

Specifically, the exterior surface 410 includes a central protrusion 414that defines a bore 416 and that is surrounded by a plurality ofreceivers 412 (e.g., bores). Correspondingly, the retaining element 472,which extends from an interior surface 474 to an exterior surface 476,defines bores 478 configured to align with the receivers 412 and acentral bore 479 that aligns with the protrusion 414. As can be seen,the bores 478 of the depicted embodiment are countersunk to minimize thedistance that couplers 495 installed therein extend beyond the exteriorsurface 476. Meanwhile, the central bore 479 can sit on the protrusion414 of the closure element 402 to center the retaining element 472 onthe exterior surface 410 of the closure element 402 while the couplers495 are installed through bores 478 and into receivers 412.

Still referring to FIGS. 4 and 5 , but now in combination with FIG. 8 ,perhaps the most important aspect of the retaining assembly 470 is thatthe interior surface 474 of the retaining element 472 bounds a channel434 defined by the closure section 430 when the retaining assembly 470is installed on the closure element 402. More specifically, in thedepicted embodiment, when the retaining assembly 470 is coupled to theclosure element 402, the seating section 438 provides an upstream wallof a channel 434 and the interior surface 474 of the retaining assembly470 provides a downstream wall for channel 434. Thus, coupling theretaining assembly 470 to the closure element 402 may retain or secure aseal 460, either alone or with a seal carrier 462 (i.e., a spacer),within channel 434, as is shown best in FIG. 8 . In differentembodiments, different seals 460 and/or seal carriers 462 may beutilized to extend the lifespan of the closure assembly 400 and/or thefluid end within which it is installed.

To be clear, while the Figures described thus far depict a non-circularclosure assembly 400 as a plug-style closure assembly, the sameprinciples, structures, and/or features may also be applicable to asleeve-style/type closure element and could be used to close and/or sealother non-circular segments of a fluid end, such as a non-circularversion of segment 2226. That is, although not shown herein, asleeve-style, non-circular closure assembly 400 may extend betweencasing 206 and a packing arrangement. Thus, in some instances,non-circular closure assembly 400 disposed in segment 2226 may bereferred to as a packing sleeve. For the purposes of this application, asleeve- or plug-style closer element may be referred to as a stationaryclosure element. However, the techniques presented herein need not belimited to stationary closure elements and may also be used incombination with plungers or other movable closure elements, which, forthe purposes of this application, may be referred to as movable closureelements. That is, the non-circular concepts presented herein could alsobe applied to and/or utilized with packing elements.

More specifically, the concepts presented herein (e.g., in connectionwith closure assembly 400) may be applied to a packing arrangement and amovable closure element. That is, a sleeve-style, non-circular closureassembly may embodied as a packing arrangement and plunger. In suchinstances, the plunger 202 acts as a closure element and the packingacts as a seal element to form a sealing assembly for the closureassembly presented herein. To be clear, for the purposes of thisapplication, a sealing assembly formed from a packing arrangement andplunger may be referred to as a sealing assembly for a movable closureelement. By comparison, sealing assemblies embodied as plug-style orsleeve-style closure elements (with seal elements disposed around astationary closure element) may be referred to as sealing assemblies forstationary closure elements.

Now turning to FIGS. 6 and 7 , but with continued reference to FIG. 4 aswell, the non-circular segment 3224 is generally configured to mate withthe various portions of the closure assembly 400. In the depictedembodiment, this is achieved with a non-circular segment 3224 that isentirely non-circular. More specifically, the non-circular segment 3224includes an access section 320, a sealing section 330, and a seat 332that are each non-circular. In fact, the access section 320, the sealingsection 330, and the seat 332 of the depicted embodiment each have anelongated oval shape, matching the closure assembly.

However, to be clear, for the purposes of this application a fluid endsegment may be “non-circular” when one or more portions of the segmentis/are non-circular. For example, in some embodiments, the seat 332 maybe non-circular and the sealing section 330 and/or the access section320 may be circular. As a specific example, the access section 320 couldhave any shape provided that a radius (or major dimension) of the accesssection 320 is larger than the narrow overall dimension 444 of theclosure assembly 400. This will ensure that the closure assembly 400 canbe inserted through the sealing section 330 and into the seat 332 (orinto the pumping chamber 308, at least temporarily, as is explained infurther detail below). Meanwhile, the sealing section 330 can have anyshape configured to mate with the channel 434 of the closure assembly400 so that a seal 460 disposed in the channel 434 can seal against thesealing section 330.

Regardless of which sections of non-circular segment 3224 arenon-circular, overall, the non-circular segment 3224 is dimensioned toallow the closure assembly 400 to be inserted through the non-circularsegment 3224. More specifically, overall, the non-circular segment 3224includes a minimal narrow dimension 342 and a minimal elongateddimension 344. Each of these dimensions is configured to allow theclosure assembly 400 to be inserted through the non-circular segment3224 when the closure assembly 400 is disposed in an installationorientation O1 (see FIGS. 18A-18E).

To achieve this, the minimal narrow dimension 342 is larger than a depthof the closure assembly 400, or at least the depth of the closureelement 402 (insofar as “depth” is a dimension perpendicular to bothnarrow overall dimension 444 and elongated overall dimension 442).Meanwhile, the minimal elongated dimension 344 is larger than the narrowoverall dimension 444 of the closure assembly 400, or at least a narrowdimension of the closure element 402. Thus, when the narrow overalldimension 444 of the closure assembly 400 is aligned with the minimalelongated dimension 344 of the non-circular segment 3224 and the depthof the closure assembly 400 is aligned with the minimal narrow dimension342 non-circular segment 3224, the closure assembly 400 (or the closureelement 402) may be inserted through the non-circular segment 3224. Thatis, when the closure assembly 400 (or the closure element 402) is in aninstallation orientation O1, the closure assembly 400 (or the closureelement 402) may be inserted into and through the non-circular segment3224.

Another important aspect of the non-circular segment 3224 is its seat332. The seat 332 is configured to support the closure element 402 and,more specifically, to support the seating section 438 of the closureelement 402. At the same time, the seat 332 forms a fluid barrier thatis essentially in the pumping chamber 308 and, thus, the seat 332 mayexperience a large amount of wear. Accordingly, the seat 332 includescontoured edges 334 that are designed to smooth the transitions from thepumping chamber 308 and/or from the inlet segment 2126 to the seat 332and reduce or prevent wear on the casing 306. Notably, the contourededges 334 eliminate corners, which can be susceptible to wear, betweenthe inlet segment 2126, the pumping chamber 308, and the seat 332. Thismay be particularly important, since the seat 332 may be hard to accessfor repairs.

Now turning generally to FIGS. 9-17 , these Figures generally depictvariations and/or modifications of a non-circular bore and/or anon-circular closure assembly, as compared to the embodiments of FIGS.3-8 . For brevity, the description of FIGS. 9-17 focuses on differencesbetween the embodiments and does not reiterate descriptions of likecomponents. Instead, FIGS. 9-17 are labeled with like reference numeralswhere applicable and any description of like parts or componentsincluded in this application should be understood to apply to likenumbered parts. However, to be clear, the variations and modificationsdepicted in FIGS. 9-17 should not be interpreted to limit the presentapplication to certain modifications or variations in any manner.Likewise, if a certain difference is not described in detail, thisomission should not be interpreted to require that certain parts,components or features must be the same across different embodiments.

That all said, in FIG. 9 , a modified non-circular segment 3224′ isdepicted from a side, sectional view. As can be seen, the non-circularsegment 3224′ is substantially similar to non-circular segment 3224,except that the non-circular segment 3224 includes an access section 321that is counter-bored instead of tapered (like access section 320). Thiscounter-bored access section 321 may be advantageous because it mayprovide easier access to the sealing section 330 and/or seat 332, whichmay ease servicing and/or manufacturing. As mentioned, manufacturingnon-circular bores may be somewhat complicated and, thus, the accessafforded by access section 321 may be particularly advantageous for thetechniques presented herein.

Next, in FIG. 10 , the closure assembly 400′ is shaped substantiallysimilar to the closure assembly 400, but is now only formed from aclosure element 402′. That is, closure assembly 400′ includes a closureelement 402′ that is self-retaining and does not include a retainingassembly (like retaining assembly 470). To compensate for this, theclosure element 402′ includes an exterior surface 410′ with a radialsurface 411 that extends radially beyond the closure section 430. Thus,channel 434′ is defined between the shoulder 436 and the radial surface411 of the exterior surface 410′.

One other notable difference is that the closure element 402′ includesinstallation elements 450 extending outwardly, away from the exteriorsurface 410′. The installation elements 450 provide a grip point on theexterior surface 410′ that can be used during installation and/orremoval of the closure element 402 from a non-circular segment 3224. Inthe depicted embodiment, the installation elements 450 comprise twoU-shaped bars that extend along the narrow overall dimension 444 of theclosure element 402′, on either side of a central bore 416′. However, inother embodiments, the installation elements 450 may have any shapeand/or may extend in any direction, across any portion of the exteriorsurface 410′. But, at the same time, it may be beneficial to arrange theinstallation elements 450 symmetrically and/or evenly with respect to acenter of the exterior surface 410 (e.g., around and/or with respect tobore 416′ because symmetrically or evenly spaced installation elements450 may allow for linear translation that avoids tilting or rotation.The bore 416′ may also be helpful for installation, removal, and/orsecuring the closure element 402′ within a non-circular segment 3224.

FIGS. 11 and 12 depict yet another embodiment of the non-circularclosure assembly presented herein. In this embodiment, the closureassembly 500 includes the closure element 402 and the retaining element472 of FIGS. 3-8 , but now the retaining assembly 470 also includes acrossbar 502 and an extended coupler 504. As can be seen in FIG. 11 ,the crossbar 502 extends across the non-circular segment 3224 (e.g.,across the access section 320), so that the crossbar 502 can sit outsidethe external surface 310 of the casing 306. Then, the crossbar 502 cansupport an extended coupler 504 that stretches from the external surface310 to the closure element 402. Thus, the crossbar 502 and extendedcoupler 504 can further secure the closure element 402 in place in thenon-circular segment 3224 (e.g., on a seat 332) and, among otheradvantages, prevent the closure element 402 from being pushed into orsucked out of the non-circular segment 3224 (or more specifically of theseat 332).

FIGS. 13-15 depict an embodiment that is similar to the embodiment ofFIGS. 11 and 12 ; however, now closure assembly 600 includes retainingassembly with a crossbar 502′ and extended coupler 504′ that aresupported by an annular ring 602 on the external surface 310 of thecasing 306 (i.e., disposed exteriorly of casing 306). The annular ring602 extends from an interior surface 606 to an exterior surface 608. Theinterior surface 606 abuts the external surface 310 of casing 306 whenthe annular ring 602 is installed thereon. Additionally, the annularring 602 extends from an internal surface 604 that surrounds and/ordefines the exterior opening of the non-circular segment 3224″ to anexternal surface 610.

In the depicted embodiment, both the internal surface 604 and theexternal surface 610 are non-circular. However, in other embodiments,the annular ring 602 need not include a non-circular internal surface604 and a non-circular external surface 610. For example, the externalsurface 610 might be circular or the overall annular ring 602 might haveany desirable shape that can secure the crossbar 502′ to the externalsurface 310. The key is that the internal surface 604 extends at leastpartially over/within the exterior opening of the non-circular segment3224″ so that the interior surface 606 can define a shoulder at aproximal end of the non-circular segment 3224″. In the embodimentdepicted in FIGS. 13-15 , the non-circular segment 3224″ hassubstantially constant dimensions (e.g., a single non-circular shape)and, thus, the interior surface 606 may be sized based off of a singlenon-circular shape. However, this non-circular segment 3224″ is merelyan example provided for simplicity and, in other embodiments, theannular ring 602 can be used with any desirable non-circular segment.For example, in other embodiments, the annular ring 602 may be sized tomate with, and extend partially over, a proximal end of an accesssection of a non-circular bore (e.g., access section 320 or 321).

Additionally, in the embodiment of FIGS. 13-15 , the closure assembly600 includes a closure element 402″ that does not include a fullybounded seal channel (e.g., like channel 434). Instead, closure element402″ defines a channel 434′ that is defined by the closure section 430,bounded on an upstream side by the seating section 438, and open on adownstream side. Then, as can be seen best in FIG. 15 , a seal carrier660 extends between the interior surface 606 of the annular ring 602 andthe shoulder 436 of the closure element 402″ to support a seal 460between the closure element 402″ and the non-circular segment 3224″. Indifferent embodiments, the seal carrier 660 may support the seal 460 inany desirable location between the shoulder 436 and the interior surface606 of the annular ring 602.

FIGS. 16 and 17 depict another embodiment that utilizes an annular ring602 as part of the retaining assembly; however, now, the closureassembly 700 includes a closure element 402′″ that is secured adjacentthe external surface 310 of the casing 306. One notable advantage ofthis embodiment is that the closure element 402′″ is configured to sealagainst the annular ring 602 and, thus, any wear from this seal occurson a replaceable part (annular ring 602). More specifically, the closureelement 402′″ resembles the self-retaining closure element 402′ of FIG.10 , but without the installation elements 450, and thus, defineschannel 434′ between its seating section 438 and its exterior surface410. Meanwhile, the annular ring 602 is configured to extend at leastpartially within the lateral bounds of the non-circular segment 3224″ sothat the channel 434′ can sit against the internal surface 604 of theannular ring 602, sealing there against.

More specifically, the seating section 438 of the closure element 402′″may sit against the interior surface 606 of the annular ring 602, whichmay secure/retain the closure element 402′″ within the non-circularsegment 3224″ when the closure element 402′″ is disposed in an operationorientation O2. At least because the closure element 402″ is securedwithin the non-circular segment 3224″ adjacent the external surface 310(and the annular ring 602), the coupler 504″ need not be extended. Thismay also be advantageous because it may reduce the chances that thecoupler 504 experiences stresses or torques (e.g., due to misalignment).Also, to be clear, this embodiment is again depicted with a relativelystraight/constant, non-circular segment 3224″, but the non-circularsegment 3224″ is, again, only provided as a example and the concepts ofthis embodiment need not be limited to such bores.

Now turning to FIGS. 18A-18E, these Figures diagrammatically depict amethod of closing an externally open segment of a fluid end of areciprocating pump with a closure assembly. Initially, as is shown inFIG. 18A, a first step 802 involves orienting a closure element 402 inan installation orientation O1 and arranging the closure element 402 forinsertion into a non-circular segment 3224. As mentioned, in at leastsome embodiment, the installation orientation O1 aligns a depth of theclosure element 402 with a narrow dimension of the non-circular segment3224 and aligns a narrow dimension of the closure element 402 with anenlarged dimension of the non-circular segment 3224. Thus, onceorientated in the installation orientation O1, the closure element 402can be translated along a lateral axis A1 in a first lateral directionD1. This translational movement moves the closure element 402 throughthe non-circular segment 3224, from the external surface 310 of thecasing 306 to the pumping chamber 308 of the casing 306.

In a second step, the closure element 402 is rotated from itsinstallation orientation O1 to an operational orientation O2 that isangularly offset from the installation orientation O1. For simplicity,this step is depicted in two sub-steps: sub-step 804(1) and sub-step804(2); however, in other embodiments, this step can be accomplished inone or more operations. For example, the closure element 402 may berotated about two axes at one time. That said, in FIGS. 18B and 18C, tworotations are shown.

First, in sub-step 804(1), the closure element 402 is rotated aboutlateral axis A1 in a first rotational direction D2. For example, theclosure element 402 may rotate approximately ninety degrees. This mayalign the narrow dimension of the closure element 402 with the narrowdimension of the non-circular segment 3224 and, thus, in at least someembodiments, it might not be easy to remove the closure element 402 fromthe pumping chamber 308 via the non-circular segment 3224 after thisfirst rotation. But, since the depth of the closure element 402 may nowbe aligned with the enlarged dimension of the non-circular segment 3224,it may still be possible to remove the closure element 402 from thepumping chamber 308.

Then, in sub-step 804(2), the closure element 402 is rotated about depthaxis A3 in second rotational direction D3. For example, the closureelement 402 may rotate approximately ninety degrees. This rotates theenlarged dimension of the closure element 402 into alignment with theenlarged dimension of the non-circular segment 3224 and, thus, orientsthe closure element 402 for seating in the non-circular segment 3224.That is, after rotating the closure element 402 about two axes, theclosure element 402 may be disposed in an operational orientation O2.

Next, in step 806, the closure element 402 is translated is translatedalong lateral axis A1 in a second lateral direction D4, as is shown inFIG. 18D. The second lateral direction D4 is opposite to the firstlateral direction D1 and, thus, this translation moves the closureelement 402 towards and/or further into the non-circular segment 3224,causing the closure element 402 to seat in the non-circular segment3224, eventually moving into installation position P1 (see FIG. 18E).The final seating may also require some lateral adjustments along alongitudinal axis A2, depending on the position of the closure element402 after the rotation(s).

Notably, in FIGS. 18A-18E, the closure element 402 is installed byitself. In some embodiments (e.g., the embodiment of FIG. 10 ), theclosure element 402 may be able to retain a seal on its own and, thus,may define an assembly 401 without any further components. This sealingassembly 401 may also be self-retaining (e.g., like the embodiment ofFIG. 10 ) and, thus, installation of the closure assembly 400 may, insome instances, be complete after step 806. However, in otherembodiments, the closure assembly 400 may include a retaining assembly470 that secures and/or retains the closure element 402 and/or a seal406 within the non-circular segment 3224. For example, step 808 mayinvolve installing a seal 406 and/or a retaining assembly 470 onto aclosure element 402 positioned/seated in the installation position P1 tosecure the closure element 402 within the 3224. Alternatively, any ofthe other retaining assemblies depicted herein, or variations thereof,might be installed on a fluid end casing after the sure element 402positioned/seated in the installation position P1.

Still further, some components of a closure assembly formed inaccordance with the present application might be installed prior tocompleting the method of FIGS. 18A-18E. For example, an annular ring(e.g., annular ring 602) might be installed on external surface 310 andleft in place before installation and subsequent to removal of a closureelement, if desired. In some embodiments, this could reduce downtimeduring servicing if, for example, the annular ring includes a largenumber of couplers while the closure element 402 can be installed orremoved without removing any couplers (or a single extended coupler504). To be clear, the installation process may be suitable for, or canbe slightly modified for, any embodiment, variation, or modificationpresented herein.

While the invention has been illustrated and described in detail andwith reference to specific embodiments thereof, it is nevertheless notintended to be limited to the details shown, since it will be apparentthat various modifications and structural changes may be made thereinwithout departing from the scope of the inventions and within the scopeand range of equivalents of the claims. In addition, various featuresfrom one of the embodiments may be incorporated into another of theembodiments. For example, a retaining ring or any other component of aretaining assembly shown with one embodiment of a closure element can beused with any desirable closure element to forma closure assembly of thepresent application. Accordingly, it is appropriate that the appendedclaims be construed broadly and in a manner consistent with the scope ofthe disclosure as set forth in the following claims.

It is also to be understood that the sealing assembly described herein,or portions thereof may be fabricated from any commonly used sealmaterials, such as homogeneous elastomers, filled elastomers, partiallyfabric reinforced elastomers, and full fabric reinforced elastomers.Suitable resilient elastomeric materials includes, but re not limitedto, thermoplastic polyurethane (TPU), thermoplastic copolyester (COPE),ethylene propylene diene monomer (EPDM), highly saturated nitrile rubber(HNBR), reinforced versions of the foregoing materials, such as versionsreinforced with fibers or laminations of woven material, as well ascombinations of any of the foregoing materials.

Similarly, it is intended that the present invention cover themodifications and variations of this invention that come within thescope of the appended claims and their equivalents. For example, it isto be understood that terms such as “left,” “right,” “top,” “bottom,”“front,” “rear,” “side,” “height,” “length,” “width,” “upper,” “lower,”“interior,” “exterior,” “inner,” “outer” and the like as may be usedherein, merely describe points of reference and do not limit the presentinvention to any particular orientation or configuration. Further, theterm “exemplary” is used herein to describe an example or illustration.Any embodiment described herein as exemplary is not to be construed as apreferred or advantageous embodiment, but rather as one example orillustration of a possible embodiment of the invention.

Finally, when used herein, the term “comprises” and its derivations(such as “comprising”, etc.) should not be understood in an excludingsense, that is, these terms should not be interpreted as excluding thepossibility that what is described and defined may include furtherelements, steps, etc. Meanwhile, when used herein, the term“approximately” and terms of its family (such as “approximate,” etc.)should be understood as indicating values very near to those whichaccompany the aforementioned term. That is to say, a deviation withinreasonable limits from an exact value should be accepted, because askilled person in the art will understand that such a deviation from thevalues indicated is inevitable due to measurement inaccuracies, etc. Thesame applies to the terms “about” and “around” and “substantially.”

1-13. (canceled)
 14. A fluid end of a reciprocating pump, comprising: acasing including intersecting conduits that collectively define aplurality of segments extending from an external surface of the casingto a pumping chamber defined within the casing, wherein at least aportion of at least one segment of the plurality of segments has anon-circular cross-sectional shape configured to receive and secure aclosure element with a non-circular cross-sectional shape.
 15. The fluidend of claim 14, wherein the portion of the at least one segment of theplurality of segments that has the non-circular cross-sectional shapecomprises a segment portion adjacent to the pumping chamber.
 16. Thefluid end of claim 14, wherein the portion of the at least one segmentof the plurality of segments that has the non-circular cross-sectionalshape comprises a segment portion adjacent to the external surface ofthe casing.
 17. The fluid end of claim 14, wherein the plurality ofsegments include: an intake segment that provides a fluid inlet for thepumping chamber; a discharge segment that that provides a fluid outletfor the pumping chamber; a reciprocation segment configured to operablycouple a reciprocating component to the pumping chamber so that thereciprocating component can draw fluid into the pumping chamber via theintake segment and discharge fluid from the pumping chamber via thedischarge segment; and an access segment that provides access to atleast the pumping chamber.
 18. The fluid end of claim 17, wherein theaccess segment has the non-circular cross-sectional shape. 19.(canceled)
 20. (canceled)
 21. The fluid end of claim 17, wherein theintake segment has the non-circular cross-sectional shape.
 22. The fluidend of claim 17, wherein the discharge segment has the non-circularcross-sectional shape.
 23. The fluid end of claim 17, wherein thereciprocation segment has the non-circular cross-sectional shape. 24.The fluid end of claim 14, wherein the at least one segment of theplurality of segments that has the non-circular cross-sectional shapecomprises: an access section proximate the external surface of thecasing; a seat positioned proximate the pumping chamber; and a sealingsection positioned between the access section and the seat, the seatbeing configured to retain the closure element in a position where theclosure element can seal against the sealing section.
 25. The fluid endof claim 24, wherein the access section, the seat, and the sealingsection are each non-circular.
 26. The fluid end of claim 24, whereinthe seat comprises contoured edges configured to smooth a transitionfrom the pumping chamber to the seat, a transition from another segmentof the plurality of segments to the seat, or both.
 27. The fluid end ofclaim 14, wherein the non-circular cross-sectional shape is an elongatedovular shape.
 28. The fluid end of claim 14, wherein the at least onesegment of the plurality of segments with the non-circularcross-sectional shape is tapered.
 29. A fluid end of a reciprocatingpump, comprising: a casing including intersecting conduits thatcollectively define a plurality of segments extending from an externalsurface of the casing to a pumping chamber defined within the casing,wherein at least one segment of the plurality of segments has anon-circular cross-sectional shape configured to receive and secure aclosure element, and wherein the plurality of segments include: anintake segment that provides a fluid inlet for the pumping chamber; adischarge segment that that provides a fluid outlet for the pumpingchamber; a reciprocation segment configured to operably couple areciprocating component to the pumping chamber so that the reciprocatingcomponent can draw fluid into the pumping chamber via the intake segmentand discharge fluid from the pumping chamber via the discharge segment;and an access segment that provides access to at least the pumpingchamber.
 30. The fluid end of claim 29, wherein the access segment hasthe non-circular cross-sectional shape.
 31. The fluid end of claim 29,wherein the intake segment has the non-circular cross-sectional shape.32. The fluid end of claim 29, wherein the discharge segment has thenon-circular cross-sectional shape.
 33. The fluid end of claim 29,wherein the reciprocation segment has the non-circular cross-sectionalshape.
 34. A fluid end of a reciprocating pump, comprising: a casingincluding intersecting conduits that collectively define a plurality ofsegments extending from an external surface of the casing to a pumpingchamber defined within the casing, wherein at least one segment of theplurality of segments comprises: an access section proximate theexternal surface of the casing; a seat positioned proximate the pumpingchamber; and a sealing section positioned between the access section andthe seat, the seat being configured to retain a closure element in aposition where the closure element can seal against the sealing section,wherein at least one the access section, the seat, and the sealingsection has a non-circular cross-sectional shape.
 35. The fluid end ofclaim 34, wherein the at least one segment of the plurality of segmentscomprises an access segment that provides access to at least the pumpingchamber.